Hi, I live in Brooklyn, where I am the Landlord at our three-unit house; this involves waiting for things to suddenly go wrong and then trying to figure out how to repair them and pay for them. My wife is a math professor, & our son is at college in New England and we miss him. We have three cats so, with our son at school, my wife and I are outnumbered.

I collected banknotes at different times in my life and I'm active again after a long time doing other things. (We had a kid.)
I have different interests--at the moment I have:
> some pre-1914 notes from Austria-Hungary and the German & Russian Empires
> a $20 bill from the Republic of Texas, which my wife got me as a birthday gift (I am from Texas, and one of my ancestors settled there while it was part of Mexico)
> a French Revolutionary 25 livres assignat (grandfather of the Mexico/Texas settler was a Jacobin)
> some Dutch guilders from the 1990s I brought back from Amsterdam that are beautifully designed; it's a shame it's all been replaced by boring unfoldable Euronotes (I have no Dutch ancestors, but New York does)
> a plastic $20 I brought back from Canada recently (I am not Canadian, but I am a hockey fan) which has me wondering if the age of paper banknotes is drawing to a close (I assume we will always need ~2% of economy in the form of currency and coin, tangible money.
I have some of those inexpensive old Cambodian (pre-1975) and Thai notes around here, a couple of old French Franc notes, some other world notes. Things I bought that looked interesting. Outside of banknotes I own a couple of pieces of incunabula--pages from books printed in 1478 & 1500 I bought from an old bookstore in Manhattan that went out years ago. Maybe because I used to be a proofreader. (I married a typesetter, too, the math gig was later.) But I'm not into things like bonds, certificates, etc. (see proofreader, above). I was given some old coins as a kid, which were very interesting, but when I came across a $2 bill in 1972 I was hooked.
Mainly it's been (1) big old notes from dead empires, (2) vertical notes, (3) pre-Euro notes from late 20th c., (4) notes with interesting alphabets, preferably in interesting designs, (5) the Republic of Texas, & (6) the Queen on old or unusual notes from places people don't know exist (Jersey, Guernsey, Isle of Man, or Gibraltar, mostly). And always $2 bills.
Collecting intentions: I have plans to get one or two large (pre-1928) US notes each year & assemble a nice little album. I've always wanted to collect large notes but have never been able to afford them. I'm looking to only buy VF20-grade and up, the higher the better, yet stay below $200 a note, meaning I'm willing to go over $200 in a couple of cases and maybe accept a F8 $1 Gold Certificate around $200 because I think they're cool. This is about the same as my plans re fractional notes. This all depends on having a few thousand dollars lying around here and there over the next few years, & so it may not happen (see Landlord, above).
I'm still getting up to speed. I will lurk for a while and get my bearings, so may not post much at first. I got some currency pages on
ebay which are archive-grade and won't leach oils, I'm learning this 1-70 grading system adapted from coin grading (we only had U, XF, VF etc. when I did this last). I have some old UK coins, which I like because of the old £ s. d. (pre-decimalization) system with the weird coins like half-crowns and florins and farthings, but other than that my interests are focussed on banknotes, which is why I'm banknotorious.